The sharply higher death toll came as the U.N. human rights chief faulted Congo's government for failing to protect civilians, citing "harrowing" reports from U.N. rights experts

KINSHASA, Congo – More than 3,300 people have been killed in central Congo’s volatile Kasai provinces since August, according to a document released Tuesday by the Catholic church, as the United Nations called for an international investigation after accounts of babies with machete wounds and pregnant women sliced open.

The sharply higher death toll came as the U.N. human rights chief faulted Congo’s government for failing to protect civilians, citing “harrowing” reports from U.N. rights experts deployed this month to interview displaced people.

“My team saw children as young as two whose limbs had been chopped off; many babies had machete wounds and severe burns,” Zeid Ra’ad al-Hussein said in his report to the U.N. Human Rights Council. “One 2-month-old baby seen by my team had been hit by two bullets four hours after birth; the mother was also wounded. At least two pregnant women were sliced open and their fetuses mutilated.”

The government soon will publish its own report on the crisis, Congolese government spokesman Lambert Mende told press.

“Beyond verifying whether these figures are true or not, it demonstrates that this is a real security situation that must absolutely lead to an appropriate government reaction to put an end to this,” Mende said.

The region in central Congo exploded into violence after a traditional chief known as Kamwina Nsapu was killed in a military operation in August after his militants revolted against Congolese authorities.

The subsequent fighting had been blamed for 400 deaths before the Catholic church released the figure of 3,300 on Tuesday. Among the victims were two foreign U.N. experts — American Michael Sharp and Zaida Catalan, a Swedish-Chilean national.

Militants loyal to Nsapu filmed themselves killing the two experts, who had been investigating allegations of human rights abuses. Their bodies were later found in a shallow grave along with the body of their Congolese colleague.

The U.N. human rights chief said the situation has become more complex in recent months. In addition to the Kamwina Nsapu fighters, another militia has arisen to defend civilians against the attacks.

This group, known as Bana Mura, is now implicated in human rights abuses as well, the U.N. said.

“Refugees from multiple villages in the Kamonya territory indicated that the Bana Mura have in the past two months shot dead, hacked or burned to death, and mutilated, hundreds of villagers, as well as destroying entire villages,” Zeid said.

“Victims also reported that members of local units of the Congolese army and police, as well as some traditional chiefs, have accompanied some Bana Mura attacks, and said some state agents are involved in arming and directing the militia,” he added.